1. Field of the Invention
The present invention relates generally to support assemblies, and more particularly to a support assembly for retaining a coffee filter against the inside wall of the coffee brewing basket in automatic drip coffee makers.
2. Description of the Prior Art
Devices for retaining the coffee filter against the wall surface of a basket in automatic drip coffee makers generally are well known. Such devices are designed to prevent a portion of the coffee filter from sagging away from the wall of the basket and allowing coffee grinds to fall between the basket and the filter and thence into the coffee pot.
For example, U.S. Pat. No. 4,656,932 discloses a contractible annular member disposed inside the filter and adapted to urge the filter against the wall of the coffee brewing basket. The inside diameter of the annular member may be altered by sliding one portion thereof relative to another. A series of clips frictionally engages the portions and maintains them in their adjusted position.
Similarly, U.S. Pat. No. 4,963,262 comprises a one-piece retainer ring sized and shaped to fit inside the coffee brewing basket so that the coffee filter is sandwiched between the wall of the basket and the retainer ring.
Other devices of this same general type are disclosed in U.S. Pat. No. 4,735,719 (a frusto-conical retainer ring with an annular flange at the top); U.S. Pat. No. 4,865,737 (a cylindrical structure of woven mesh sized to fit into baskets of different shape and size); and U.S. Pat. No. 4,981,588 (a support member adapted to supported on the rim of a cup and to support, in turn, a filter member extending into the cup).
Each of the above patented devices suffers from the disadvantage of not being "automatically" adjustable to fit varying sized coffee brewing baskets and maintaining a snug fit without undue attention. Although the prior annular member of the '932 patent is adjustable, it must be manually manipulated by trial and error before the right size for a particular basket is obtained. None of the other coffee filter support devices shown in the prior art discussed above includes means for automatically adjusting the fit of the coffee filter support assembly to accommodate the particular basket it is being employed with. This important disadvantage is overcome and other advantages are achieved only by the present invention as will be made apparent from a study of the remainder of the specification which follows.